Airspace that is navigable by aircraft is divided into different types (e.g., classes and/or categories) of three-dimensional sections. Most nations typify airspace sections consistent with those delineated by the International Civil Aviation Organization (ICAO). Some nations, including the United States, include additional airspace types, generally referred to as Special Use Airspace, for which additional rules and restrictions may apply.
In the United States, there are two general categories of airspace, regulatory and non-regulatory. The regulatory airspace is divided into eight different airspace types, referred to as Class A, B, C, D, E, and G airspace areas, restricted airspace areas, and prohibited airspace areas. The non-regulatory airspace are divided into four different airspace types, which are referred to as military operations areas (MOAs), warning areas, alert areas, and controlled firing areas. The regulatory and non-regulatory airspace categories may additionally include airspace subcategories. These airspace subcategories are referred to as controlled airspace, uncontrolled airspace, special use airspace, and other airspace.
The categories and subcategories assigned to particular airspaces are dictated by several factors (e.g. density of aircraft movements, the nature of the operations, and national or public interest), and each airspace has its own set of associated regulations. For example, Class B airspace is a controlled airspace which generally extends from the surface of the earth to ten thousand feet from mean sea level surrounding the nation's busiest airports in terms of airport operations or passenger enplanements. Aircraft that enter Class B airspace must be given clearance by air traffic control and must abide by speed, separation, and other regulations.
Airspace violations have occurred due to the unavailability of alerting information to pilots regarding the various classes of airspace and the restrictions associated therewith. Current display systems do graphically represent altitude information associated with a particular class of airspace; however, they do not display the associated speed limitations since pilots may be overwhelmed due to the abundance of displaced information.
To assist pilots in identifying airspaces and their associated restrictions, many aircraft are equipped with an avionics display system that graphically render a moving map, which includes a depiction of the airspaces around the aircraft. Data about each airspace (e.g. class, altitude range, etc.) may be displayed as text overlaid onto the moving map. However, such systems do not display speed restrictions associated with a type of class of airspace.
In view of the forgoing, it would be desirable to provide a navigation display system to graphically display the airspaces and their associated speed data in a readily comprehensible manner. This would reduce a pilot's workload during flight and provide for better position and situational awareness.